Technical Abstract:
Rambutan disease surveys were conducted and a variety of fungal pathogens were isolated and identified as the causal agents of fruit and leaf leasions. Our overall goal is to gain a better understanding of what fungi affect rambutan fruit quality and determine if pathogen management practices can result in improved fruit quality. The fungi identified included Lasmenia, Colletotrichum, Phomopsis, Lasiodiplodia and Pestalotiopsis. Growth studies at a variety of temperatures were conducted to determine if certain temperatures could suppress disease. Disease incidence was compared for six rambutan varieties. Fungal isolates were also evaluated for sensitivity to fungicides registered for use in Hawaii. Until recently, lychees in Hawaii were relatively free of pre-harvest diseases affecting fruit or foliage. This research aims to benefit the lychee industry in Hawaii by establishing the extent of disease problems, raising awareness of the incidence and damage, and eventually evaluate some potential control measures. Since growers may be unaware of the symptoms of lychee diseases and consider them as an unspecified "blemish", it was felt that growers would immediately benefit from accurate identification and early intervention.